By 1971, Michael Apted, the key figure behind the groundbreaking documentary series Seven Up (ITV, 1964-), had developed an impressively unobtrusive camera style. Another Sunday and Sweet F.A., his collaboration with writer Jack Rosenthal, has a similar sense of the observational about it. Influenced presumably by the approach pioneered in the previous decade by Ken Loach and others, much of the drama is documentary in feel and certain sequences show evidence of improvisation.

Not much happens in this tale of an amateur football match refereed by the upright but ineffectual Eric Armistead, but the accumulation of detail exudes authenticity. The camera glides past the changing rooms, catching snatches of banter as the players smoke their pre-match cigarettes, and lingers on Eric, fastidiously brushing down the remaining hair around his bald pate.

To Eric, said Rosenthal, "life is an Immorality Play. Right never triumphs over wrong. Good never vanquishes evil. No one knows the meaning of 'fairness'. Which is why he's a Sunday morning referee - hoping that in his own small way, in a foreign field that's forever Manchester, he and his whistle might change the world." His treasured photo of 1920s/30s footballing icon Dixie Dean demonstrates both his delusions of grandeur and the extent to which he is behind the times.

The goal that 'accidentally' deflects off his head at the film's climax - in an echo of Brian Glover's celebrated turn in Loach's Kes (1969) - is Eric's response to taunts about his lack of talent as a young player, but completely undermines his reputation for probity. None of this matters as he finally savours the glory of victory in his own head. This sense of accomplishment, however, was not shared by David Swift. Rosenthal recalled how the actor found it impossible to head the ball, and how, with the number of takes now in the thirties, the successful shot was only captured with the use of a light, plastic toy football borrowed from an appalled young bystander.

The supporting players savour the bite of Rosenthal's dialogue. The old-timer repeating everything his manager says, only slightly reworded; the lady struggling to keep up with her friend's discourse on world affairs; the goalkeeper and his girlfriend, each trying to manoeuvre the other into a guilty apology - such characterisations spring vividly from the sparest of strokes. Little wonder that the play won Rosenthal the Critics' Circle award, the first of many honours.